The oil and gas industry is increasingly moving towards all-electric arrangements for underwater hydrocarbon extraction facilities (for example, by using electrically operated actuators). ‘All-electric’ refers to systems where some, or all, of the hydraulically driven components are instead driven by electrical means. Prior art underwater extraction facilities relied on a subsea control module (SCM) to act as a centralised controller for electrical and hydraulic actuators in an underwater hydrocarbon extraction facility. However, an all-electric arrangement, the requirements on the SCM are less rigid and control of the actuators can be distributed rather than centralised.
As prior art there may be mentioned:
U.S. Pat. No. 6,595,487, which discloses an electric actuator with primary and secondary sources of power;
EP0704779, which discloses a device for controlling hydraulically-actuated oil well head valves;
GB2264737, which discloses the remote control of hydraulically operated valves;
WO2014105420, which discloses a method of providing power to subsea sensors;
EP2474704, which discloses a method of monitoring a subsea sensor;
GB2480973, which discloses a subsea control module that can communicate with a plurality of sensors wirelessly;
GB2476740, which discloses a controller with acoustic and optical communication means; and
US20110215747, which discloses a module for supplying electrical power to an actuator in the event of a power failure.
It is an aim of embodiments of the present invention to overcome drawbacks associated with prior art actuators.